This photograph depicted ventral view of an engorged female "lone star tick" Amblyomma americanum. An Ixodes or "hard" tick, A. americanum is found through the southeast and south-central states, and has been shown to transmit the spirochete, Borrelia lonestari, the pathogen responsible for causing a Lyme disease-like rash known as "Southern tick-associated rash illness" (STARI). Representatives from all three of its life stages aggressively bite people in the southern U.S.

Epidemiology and Risk: In 2001, a patient with evidence of B. lonestari infection was reported in the medical literature. This patient had exposure to ticks in Maryland and North Carolina, and developed a rash indistinguishable from erythema migrans after an A. americanum tick bite. DNA analysis indicated the presence of B. lonestari in a skin biopsy taken at the leading edge of the rash, and in the tick removed by the physician. Serologic testing for Lyme disease was negative. The patient was treated with an oral antibiotic and returned to normal health.

Lone star ticks can be found from central Texas and Oklahoma eastward across the southern states, and along the Atlantic coast as far north as Maine. Research indicates that live spirochetes are observed in only 1-3% of specimens. Note the anal orifice located in the center of the ventral abdominal surface.

Content Providers(s): CDC/ Dr. Amanda Loftis, Dr. William Nicholson, Dr. Will Reeves, Dr. Chris Paddock

Picture & text from CDC/PHIL. For more information on source & for information on color coding used above for different types of ticks, see Tick Pictures from CDC